“…This, coupled with the highly inhomogeneous structure of the ore beds which is another feature of the wide particle size distribution, means that existing models of hydrodynamics in similar well-described chemical systems, such as trickle bed reactors, do not adequately describe the heaps. Most heap bioleaching hydrology studies have considered the use of tracers to extract hydrodynamic parameters and develop models of the liquid flow (Bouffard and Dixon, 2001;De Andrade Lima, 2006) or to study the issue of preferential flow resulting from the inhomogeneous heap structure (Decker and Tyler, 1999;O'Kane Consultants Inc., 2000;Wu et al, 2007) for which analogies to unsaturated soil hydrodynamics have proved particularly successful. However, the liquid distribution within a heap from a drip irrigation point, one of the most common methods of irrigation (Bartlett, 1998;Kappes, 2002), has not been examined in any specific detail.…”